Self-reinforced opening

ABSTRACT

A self-reinforced structural member is disclosed. The structural member includes a vertical web between a first horizontal flange and a second horizontal flange. The vertical web includes a self-reinforced opening formed from cut portions of the web.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/304,384, filed on Feb. 12, 2010, the entirety of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

This invention generally relates to structural members, and more specifically to structural members with self-reinforced openings.

It is sometimes necessary to penetrate structural members, such as I-beams, during the construction of a structure to create openings for mechanical/electrical ducts and/or cables, etc. to pass through. However, such openings typically decrease the strength (flexure, shear, and axial) of the affected structural member, requiring supplemental reinforcement of the affected region.

BRIEF SUMMARY OF THE INVENTION

One embodiment of the invention provides a self-reinforced structural member having a vertical web between a first horizontal flange and a second horizontal flange. The vertical web may include a self-reinforced opening.

In one aspect, at least one reinforcement flange may be formed from a cut portion of the web to reinforce the self-reinforced opening.

In another aspect, the at least one reinforcement flange may extend from a horizontal edge of the self-reinforced opening in a tangential direction with respect to the vertical web.

In another aspect, the at least one reinforcement flange may extend from a horizontal edge of the self-reinforced opening in a vertical direction.

In another aspect, the at least one reinforcement flange may extend from a vertical edge of the self-reinforced opening in a horizontal direction.

Another embodiment of the invention provides a method to create a self-reinforced structural member. A first cut may be created through a web of a structural member. A second and third cut may be created through the web of a structural member. The second and third cuts may intersect the first cut. A portion of the web between the first, second and third cuts may be bent to form a reinforcement flange.

In one aspect, a portion of the reinforcement flange may be welded to the web and/or at least one of the first and second horizontal flanges.

These and other embodiments of the invention are described in further detail below with reference to the following figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B respectively show a side and cross-sectional view of a structural member which has been cut in order to form a self-reinforced opening, according to an embodiment of the invention.

FIGS. 1C and 1D respectively show a side and cross-sectional view of the structural member of FIG. 1A which has been bent in order to form a self-reinforced opening, according to an embodiment of the invention.

FIGS. 2A and 2B respectively show a side and cross-sectional view of the structural member of FIG. 1A which has been bent and welded to form a self-reinforced opening, according to an embodiment of the invention.

FIG. 3A shows a side view of a structural member which has been cut in order to form a self-reinforced opening, according to an embodiment of the invention.

FIGS. 3B-3D show the structural member of FIG. 3A which has been bent and welded to form a self-reinforced opening, according to an embodiment of the invention.

FIG. 4A shows a side view of a structural member which has been cut in order to form a self-reinforced opening, according to an embodiment of the invention.

FIGS. 4B and 4C respectively show side and cross-sectional views of the structural member of FIG. 4A which has been bent and welded to form a self-reinforced opening, according to an embodiment of the invention.

FIGS. 5A-5F show exemplary cross-sections of varying structural members, which may be used in accordance with various embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

A structural member with a self-reinforced opening is disclosed. The self-reinforced opening is generally constructed from elements of a pre-formed structural member, such as an I-beam. The self-reinforced opening may be formed to increase and/or maintain the flexural and/or shear strength along portions of the structural member. The self-reinforced opening can offer a more environmentally compatible solution to prior art methods, which involved cutting and discarding portions of a structural member and placing new portions of material along conduit openings. Thus, a self-reinforced opening suffers from no significant waste or addition of material, and reduces or eliminates welding.

The implementation of the self-reinforced opening is not limited to providing conduit pathways. As the self-reinforced opening can increase flexural and/or shear strength along portions of the structural member, the self-reinforced opening can be strategically placed in structural members to compensate for expected high loads, which would otherwise not be possible for the same structural member with no self-reinforced openings. Accordingly, the use of the self-reinforced opening can avoid the use of heavier structural members which would otherwise be needed, and which results in less material being used and lowers the overall weight of the structure.

FIGS. 1A and 1B show an elongated structural member 100. Section A-A shows a cross-section of a typical structural steel beam (i.e., I-beam) with a first horizontal flange 102 and a second horizontal flange 104 connected by a vertical web 106. The flanges typically are utilized to resist flexure and the web typically resists shear. Although this example uses a steel beam, it should be understood that any structural member may be used, such as (but not limited to) a beam, column, beam-column, brace, etc. and also other structural materials, such as (but not limited to) light gauge steel and other malleable materials.

The structural member 100 has been cut in order to form a reinforced opening 112. The structural member 100 may be cut, for example, using a cutting-torch, cutting-laser, or water-jet cutting machinery. The reinforced opening 112 may be formed by bending portions of the web from the horizontal and vertical cuts extending through the web.

FIG. 1A shows one horizontal cut 108 and two vertical cuts 110 in the web 106. The cuts shown are in an “H” pattern, although other patterns may be used. The vertical cuts 110 may be curved at their top and bottom edges as shown to reduce stress concentrations.

FIGS. 1B, 1C and 1D show the structural member 100 of FIG. 1A after a self-reinforced opening 112 has been created from the cuts formed in the web 106. The self-reinforced opening 112 includes two reinforcement flanges 114 formed from the cut web 106 to create the self-reinforced opening 112. Section B-B shows a cross-section of the structural member 100 with the two sides of the cut web 106 bent to a horizontal position. Accordingly, the reinforcement flanges 114 extend from horizontal edges of the self-reinforced opening 112 in tangential directions relative to the vertical direction. The reinforcement flanges 114 may be formed by bending the cut portions of web 106 away at the intact (i.e., non-cut) edges of the opening. The reinforcement flanges 114 may be bent by using jigs and purpose built bending brakes. Portions of the web 106 may be heated while forming the reinforcement flanges 114 to enable bending.

The self-reinforced opening 112 minimally decreases flexural strength of the structural member since the web contributes little to flexural strength. The horizontal flange 102 and a second horizontal flange 104 contribute to most of the flexural strength possessed by the structural member 100. The reinforcement flanges 114 increase the flexural strength at the self-reinforced opening 112, as compared to an opening with no reinforcement. Thus, the reinforcement flanges 114 compensate for the flexural strength loss due to the self-reinforced opening 112, and may in some cases create a greater flexural strength as compared to a structural member with no openings.

Larger openings (extending in the vertical direction) accordingly result in larger reinforcement flanges which compensate for the otherwise larger loss in flexural strength. Thus, very large openings (e.g., more than 50% of the web) are possible accompanied by little flexural strength loss or even some appreciable flexural strength gain. Flexural demand is high in some regions such as the mid-span of a simply supported beam; accordingly, the self-reinforced opening 112 shown in FIGS. 1C and 1D may be advantageously placed in such regions. This embodiment can be used as a cost effective and waste minimizing way to increase the flexural strength of structural members, even if an opening is not required for mechanical/electrical ducts/cables. It should be understood that the reinforcement flanges 114 are bent in opposite directions for symmetry to avoid introducing torsional effects, but also could be turned to the same side of the web if torsional effects are minimal or mitigated in other ways.

The structural member of FIGS. 2A and 2B is similar to the structural member 100 of FIGS. 1C and 1D. However, in this embodiment the reinforcement flanges 202 are bent downwards and upwards, respectively, to become parallel with the surfaces of the web 204. Accordingly, the reinforcement flanges 202 extend from horizontal edges of the self-reinforced opening 206 in the vertical direction. Section C-C shows the reinforcement flanges 202 formed completely towards the vertical direction. The leading edges, and/or other portions, of the reinforcement flanges 202 may be welded to portions of the web and/or horizontal flanges. The reinforcement flanges 202 are turned in opposite directions for symmetry to avoid introducing torsional effects, but could be turned to the same side of the web 204 if torsional effects are minimal or mitigated in other ways. Non-reinforced openings in the web will decrease shear strength substantially, since the web contributes most of the shear strength of a structural member. However, in this embodiment the web 204 cross-sectional area does not significantly change after formation of the self-reinforced opening 206, and thus the shear strength does not decrease, but is maintained.

Larger openings (extending in the vertical direction) accordingly result in larger reinforcement flanges which compensate for the otherwise larger loss in shear strength. Thus, very large openings (e.g., up to 50%) of the web are possible, which may be accompanied by virtually no shear strength loss. Shear demand is high in some regions, such as the ends of a simply supported beam, accordingly, the self-reinforced opening 206 shown in FIGS. 2A and 2B may be advantageously placed in such regions.

In some embodiments, a plurality of openings can be made in the same member span using Section B-B of FIG. 1D in flexure critical regions and Section C-C of FIG. 2B in shear critical regions. In some embodiments, a relatively long (in the horizontal direction) opening may be formed where the cut webs turn gradually from horizontal (e.g., Section B-B of FIG. 1D) to vertical (e.g., Section C-C of FIG. 2C) as the opening travels from the flexure region to the shear region. In some embodiments, a curved or semi-circular cut is made into the web to form a curved or semi-circular reinforcement flange. Many other shapes are possible.

FIGS. 3A-3D show a structural member 300 which has been cut in order to form a relatively long (in the horizontal direction) opening with respect to the horizontal length of the structural member 300 as a whole. In an embodiment the cut is 20-50% of the length of the standard member 300. This arrangement can increase flexural and shear strength along portions of the member. Portions 302, 304, 306, and 308 of the web are thus formed from horizontal and vertical cuts in the web as shown in FIG. 3A.

Portions 302 and 304 are bent about the horizontal edges of the self-reinforced opening 310 to create two reinforcement flanges in the flexure region as shown in FIGS. 3B and 3C, which are similar to the embodiment shown in FIG. 1C. Accordingly, portions 302 and 304 may increase the flexural strength about the self-reinforced opening 310.

Portions 306 and 308 are bent about the vertical edges of the self-reinforced opening 310 as shown in Section E-E, which increases the shear strength in the shear region. Accordingly, portions 306 and 308 extend from vertical edges of the self-reinforced opening 310 in horizontal directions. Edges of the portions 306, 308 may be welded to the web. This arrangement increases the shear strength about portions 306 and 308, since the cross-sectional area has been increased.

FIG. 4A shows a structural member 400 which has been cut in order to form a relatively long (e.g., 20-50% in the horizontal direction) opening with respect to the horizontal length of the structural member 400 as a whole. The cut web 402 may be bent as a whole member to form a gradually transitioning, wave-like self-reinforced opening 404 as shown in FIG. 4B. The wave-like reinforcement flanges thus have multiple cross-sections of varying angular bends which transition in a smooth and wave-resembling manner. Section B-B is as shown in FIG. 1D, while section C-C is as shown in FIG. 2B. A wave-like transition zone 406 is formed between these sections, with a gradually changing cross-section as shown in FIG. 4C. This embodiment may help avoid stress concentration areas along the self-reinforced opening 404 by reducing angular intersections of material, as well as increase and/or maintain flexural and shear strength along portions of the structural member 400.

FIGS. 5A-5F show exemplary cross-sections of structural members which may be used in accordance with embodiments of the invention. Embodiments of the invention are not limited to cutting openings in the web of an I-beam, and accordingly can be implemented with many different types of structural members. Structural members with C-channel, angle, tee, double-angle, square-tube, and rectangular-tube cross-sections are shown. The cross-sections shown are illustrative, and other types of structural members may be used as well.

The above description is illustrative and is not restrictive. Many variations of the invention will become apparent to those skilled in the art upon review of the disclosure. For example, in some embodiments varying cross-sections may be implemented to increase/maintain flexural and/or shear strength of pre-formed composite materials, such as wood, concrete, plastic, composites, and steel/concrete structural members. In another example, self-reinforced openings are placed on the main flanges of an I-beam, as opposed to the web. In another example, a self-reinforced opening is non-symmetrical, and thus includes only one reinforcement flange there along. In another example, a self-reinforced opening is used to redirect yield along specific areas of a structural member in order to prevent catastrophic failure of a structure. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the pending claims along with their full scope or equivalents.

One or more features from any embodiment may be combined with one or more features of any other embodiment without departing from the scope of the invention.

A recitation of “a”, “an” or “the” is intended to mean “one or more” unless specifically indicated to the contrary. 

1. A self-reinforced structural member comprising: a vertical web between a first horizontal flange and a second horizontal flange, the vertical web including a self-reinforced opening.
 2. The structural member of claim 1, wherein at least one reinforcement flange is formed from a cut portion of the web to reinforce the self-reinforced opening.
 3. The structural member of claim 2, wherein the at least one reinforcement flange extends from a horizontal edge of the self-reinforced opening in a tangential direction with respect to the vertical web.
 4. The structural member of claim 2, wherein the at least one reinforcement flange extends from a horizontal edge of the self-reinforced opening in a vertical direction.
 5. The structural member of claim 2, wherein the at least one reinforcement flange extends from a vertical edge of the self-reinforced opening in a horizontal direction.
 6. A method to create a self-reinforced structural member, the method comprising: creating a first cut through a web of a structural member; creating a second and third cut through the web of a structural member, the second and third cuts intersecting the first cut; and bending a portion of the web between the first, second and third cuts to form a reinforcement flange.
 7. The method of claim 6, further comprising: welding a portion of the reinforcement flange to the web. 